1. Field of the Invention
The present invention relates to the joining of conveyor belts by means of two rows of metallic fastening staples which are coupled together by means of a hinge-pin.
2. Description of the Prior Art
The staples employed for this purpose consist of U-shaped elements which are intended to be placed astride each end of a conveyor belt in order to be secured by means of metallic clamps or any other suitable elements. These coupling staples are provided with U-shaped hinge-ends placed in a projecting position with respect to the edge of the corresponding end of the conveyor belt. The arrangement is such that the hinge-ends of two complementary rows can be disposed in interjacent relation in order to be coupled by engagement of a coupling pin within the passageway formed by said U-shaped hinge-ends.
Said coupling pin therefore permits articulation of the two corresponding rows of staples as the conveyor belt passes over a driving drum or guide drum. However, it is necessary to ensure that the coupling pin is capable of flexural deformation in the transverse direction so that the belt can accordingly assume the shape of a trough on the rollers of a conveyor when it is in service. It is for this reason that coupling pins of this type are usually constituted by a cable of twisted wire strands.
However, coupling pins of this type are subjected to high friction forces as a result of the articulation of the hinge-ends of the staples on said pins. This produces rapid wear of the coupling pins. Furthermore, there is a considerable danger of seizure of the staple hinge-ends on said coupling pins.
In an attempt to overcome these disadvantages, it has been proposed to provide around coupling pins of this type rotatable sleeves or the like which are thus interposed between the staple hinge-ends and the corresponding pin. One solution of this type is described in German patent Application No. 25 07 474. However, a solution of this type suffers from the disadvantage of being particularly costly. Furthermore, it provides only an imperfect answer to the problem under consideration, particularly as the presence of the rotatable sleeves thus provided is attended by a drawback in that the sleeves reduce the flexibility of the hinge-pin.
For the reason stated in the foregoing, the aim of the present invention is to produce a coupling pin so designed as to permit good articulation of the hinge-ends of the staples while nevertheless providing a satisfactory degree of flexibility.